# Create or update an entitlement (/api/usage-entitlements/save-usage-entitlement)

`POST https://api.comecero.com/api/v1/usage/entitlements`

A `metered` entitlement bills a metric on a pinned rate plan version. A `credit` entitlement holds prepaid credit for the agreement. Send an existing `entitlement_id` to update it: its `kind`, agreement, metric and `customer_id` can not change. It answers `201` for a create and for an update. Create a credit entitlement before a metered one that draws on it. Secret and trusted tokens may call it; a limited token may not (`403`).

Request body: the `usage_entitlement_request` schema.

Responses: 201, 400, 401, 403, 404, 409, 500.

Full schemas: operation `save_usage_entitlement` in /openapi.json.